Low pass filter-based online generator unit moment of inertia parameter identification method

Abstract

The invention discloses an online generator unit moment of inertia parameter identification method. A feature that the generator unit moment of inertia is a dynamic parameter related to a long-time constant no less than a second level is used, the generator unit moment of inertia is identified only on the basis of a generator motion equation, the phenomenon that a phasor measurement unit can not accurately measure physical quantities during a sub transient process and a transient process can be avoided, and the phenomenon that identification of the moment of inertia is influenced by inaccurate sub transient and transient parameters can be avoided. In view of the problem that generator shafting mechanical power can not be directly measured, a method of using the low-pass filter to acquire a mechanical power change curve from actually-measured electromagnetic power during a dynamic identification process is put forward, errors caused as mechanical power changes are not considered are avoided, and a long-time dynamic curve in the case of identification can be used.

Description

technical field [0001] The invention belongs to the field of generator set parameter identification, in particular to a method for on-line identification of the moment of inertia parameters of the generator set. Background technique [0002] The moment of inertia is one of the most important parameters to characterize the dynamic characteristics of the generating set, and its accuracy has an important impact on the safety and stability analysis of the power system. The moment of inertia of the generator set is determined by the sum of the moments of inertia of the rotating parts of the generator set. For example, for a thermal power unit, the moment of inertia is usually composed of the moment of inertia of the generator set, the moment of inertia of the steam turbine and the moment of inertia of the exciter (except for the generator using a static excitation system). Since these rotating parts may belong to different manufacturers and have complex structures, the moment of...

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Problems solved by technology

In order to solve the problem that the mechanical power of the generator shaft system cannot be measured, a method of using a low-pass filter to obtain the mechanical power change curve from the measured electromagnetic power curve in the dynamic identification process is proposed, so as to avoid the failure caused by the mechanical power change. The error also avoids the shortcoming that the dynamic curve that can be used for calculation cannot be too long in order to meet the premise of constant mechanical power in the test method (usually only the time curve of 100 milliseconds to 1 second can be taken)

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